There are sample icons installed by the PocketC Desktop installer with names "large1.bmp", "large2.bmp", "large8.bmp", "small1.bmp", "small2.bmp", and "small8.bmp". The digit in the name refers to the number of bits per pixel in the bitmap file.

You use @licon1 "/Program Files/PocketC/large1.bmp"
and optionally @licon2 "/Program Files/PocketC/large2.bmp"
and optionally @licon8 "/Program Files/PocketC/large8.bmp"
in your program for the large icon

and you use @sicon1 "/Program Files/PocketC/small1.bmp"
and optionally @sicon2 "/Program Files/PocketC/small2.bmp"
and optionally @sicon8 "/Program Files/PocketC/small8.bmp"
in your program for the small icon